Treatment of cellulosic fabrics



Patented Oct. 20, 1942 UNITED STATES PATENT OFFICE Q I 2,299,200 TBEATDIENT F CELLULOSIC FABRICS mamrsswrssissr acorpol'ation ofMaine No Drawing. museum October 10, 1940,

Serial No. 360,601

11CIa-ims.

This invention relates to the production of special finishes on cellulosic fabrics such as cloth and paper by means of an improved parchmentizing agent which is less destructive to the cellulosic materials because it contains a substance which delays the gelatinization of cellulosic fabrics by the parchmentizing agent.

An object of the invention is to provide an improvedmethod for applying special finishes to cellulosic fabrics. Other objects are to apply special finishes to cellulosic threads, yarns, cloth,

. paper, etc., to produce permanent organdy and voile finishes on cotton cloth, and to provide an improved method of parchmentizing paper and cloth. A still further object is to provide a new parchmentizing bath and a new class of inhibitors for such baths.

Cellulosic fabrics such as threads, yarns, cloth, paper and the like are often subjected to the action of parchmentizing agents in order to obtain certain desired effects. These parchmentizins agents, of which strong sulfuric acid is one of cellulose may be greatly inhibited by the incorporation therein of materials of the class of the destructive action of the strong acid on the the like, and may be either the same or different.

, In the preferred embodiment of my invention I dissolve parts by weight of an aminotriazine,

the most common, attack the cellulose fibers with the formation of a gelatinized material which soon dissolves in the solution. In parchmentizing processes, and in those which employ the parchmentizing principle to some degree, the gelatinizing action of the parchmentizing agent is arrested by washing it from the fiber with water when the desired degree of gelatinization has been attained.

Ordinarily only the surface of the fibers, or the surface fibers, are allowed to become gelatinized before the action of the parchmentizing agent is stopped. Concentrated sulfuric acid is, however, a very drastic gelatinizing agent and will dissolve and completely ruin delicate cellulosic fabrics in a few seconds. The element of time is therefore very critical and must be controlled with a high degree of accuracy. Some control of the gelatinizing action may be had by cooling the acid and also by using it in a more dilute form. However, since the action of weak acids on cellulose fibers is quite diiferent from that of strong acids, these methods are of limited eifectiveness. Other methods of controlling the gelatinizing action of strong sulfuric acid on cellulose fiber include the use of materials called inhibitors which appear to slow down or delay the action of the acid on the cellulose but do not materially alter the essential characteristics of the gelatinization reaction.

I have now found that concentrated sulfuric such as melamine, of the formula rim which 2.4.6-triamino-i.3.5-triazine, in 100 parts by weight of concentrated sulfuric acid. If de-. sired the mixture may be heated slightly to aid in dissolving the melamine. When the solution has cooled to room temperature it is ready for use. The cellulosic fabric to be treated may be passed through the solution in the same way as in conventional parchmentizlng processes. Due to the action of the inhibitor, however, it will be found that the material can be allowed to contact theconcentrated acid for periods of time greatly in excess of those normally thought desirable. For example, in such a parchmentizins bath as described the cellulosic fabric maf be immersed for a period of time. up to 30 seconds before wash ing 'away the acid. without ill' effects. It is understood, however, that the time of contact betwen the acid and cellulosic fabric may vary-considerably depending upon the results desired. In v some cases a few seconds in the bath may be sufficient to obtain the degree of gelatinization necessary. On the other hand, it may be desirable to leave the cellulosic fabric in the bath for more than one minute of materials. p It is apparent that the parchmentizing effect may be varied over wide limits by varying the amount of inhibitor in the strong acid bath.- with smaller amounts of aminotriazine, for exa p c i s baths y be improved and ample 2%. the inhibiting action is less but neverwhen preparing certain types The parchmentizing effect may also be varied by controlling the concentration ,of the acid so-- tuition and its temperature as in conventional parchmentizing processes mentioned above. The concentration of the sulfuric acid should be at least'52 B., however, in order to obtain the desired gelatinization of the cellulosic fimrs.

selected areas of the fabric as by printing on the fabric with the inhibited sulfuric acid solution or, alternatively, by printing a design on the cloth with a protective material such as albumin, casein, gums or paraffin and then immersing the fabric in the bath until the desired effect has been attained. Organdy and voile finishes are obtained by simply immersing unfinished cotton cloth of suitable weight in the parchmentizing Qther triazines which have been found to be effective as inhibitors in the parchmentizing bath include acetoguanamine (2-methyl-4.6-damino- 1.3.5-triazine), formoguanamine (2.4-diaminoamino-1.3.5-triazine), ammeline (2-hydroxy-4.6-'

diam'ino 1.3.5 trlazine) ammelide (2.4 dihydroxy-fi-amino-l.3.5 triazine) 2-chloro-4.6-di-' amino-1.3.5-triazlne, 2(pheny1 p-hydroxy) 4.6- diamino-l.3.5-triazine,- Z-phenyl-d-amino-G-hy droxy 1.3.5 triazine, 2.4.6-triethy1amino-1.3.5- triazine, and 2.4.S-triphenylamino-l.3.5-triazine. Various condensation products of melamine such as melam and melem may also be used as inhibitors in my process, as well as mixtures containing these compounds. Thus, for example, the mixture obtained by heating dicyandiamide abov its melting point may be used.

- The effectiveness of my inhibitors may be illustrated by means of a comparative test which was made. An 80 x 80 unfinished cotton cloth was immersed in 96% sulfuric acid. In 10 seconds visible evidence of destruction of the cloth was seen and in 30 seconds the cloth was almost completely decomposed. A piece of the same cloth was soaked ina solution of 10 g. of acetoguanamine in 100 g. of 96% sulfuric acid for more than 2 minutes. Although the parchmentiaing action of the acid solution was so stron as to almost completely gelatinize the fabric it bath and themwashing and drying as in conventional methods or" obtaining such finishes, the difference being merely that a longer time of contact. with the inhibited acid may be permitted.

In addition to the treatment of paper and cotton fabrics my invention may also be used in the treatment of fabrics made from best fibers, such as linen, and from regenerated cellulose. It

may also be used in the treatment of mercerized fabrics according art.

-What I claim is: l. A process which comprises treating cellulosic fabrics with strong sulfuric acid of parchmentlzing strength containing an aminotriazine. 2. A process which comprises treating cellulosic fabrics with strong sulfuric acid of parchmentizing strength containing 2.4.6-triamino-1.3.5-triazine.

3. A process which comprises treating cellulosic fabrics with concentrated sulfuric acid of parchmentizing strength containing 6-methyl-2.4-diamino-1.3.5-triazine.

4.-A process which comprises treating cellulosic fabrics with strong sulfuric acid of parchto methods well-known in the mentizing strength containing 2.4-diamino-l.3.5-

triazine.

5. A process which comprises treating cotton fabrics with sulfuric acid iof at least 52 B.and

containing an aminotriazine.

6. A process which comprises treating paper with sulfuric acid of at least 52 B. and containing an aminotriazine.

7. A parchmentizing agent containing sulfuric acid of. at least 52 B. concentration and an aminotriazine dissolved therein.

8. A treating agent for parchmentizing cellulose materials comprising a solution of 2 to 20 parts of an aminotriazine in sulfuric acid of at least 52 B. concentration.

9. A treating agent for parchmentizing cellulose materials comprising a solution of 2.4.6- triamino-1.3.5-triazine in sulfuric acid of at least 52 B. concentration.

. lose materials comprising a solution'of G-methyl- .2.4 -diamino-l.3.5-triazine in sulfuric acid of at a more prolonged contact which may be more 10. A treating agent for parchmentizing celluleast 52 B. concentration.

11. A treating agent for parchmentizing cellulose materials comprising a solutionof 2.4-diamino-1.3.5-triazine in sulfuric acid of at least 52 B. concentration.

PIERREPONT ADAMS. 

